1tpm2_pcrallocate(1) General Commands Manual tpm2_pcrallocate(1)
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6 tpm2_pcrallocate(1) - Configure PCRs and bank algorithms.
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9 tpm2_pcrallocate [OPTIONS] [*ARGUMENT]
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12 tpm2_pcrallocate(1) - Allow the user to specify a PCR allocation for
13 the TPM. An allocation is the enabling or disabling of PCRs and it’s
14 banks. A PCR can have multiple banks, where each bank is associated
15 with a specific hashing algorithm. Allocation is specified in the ar‐
16 gument.
17 If no allocation is given, then SHA1 and SHA256 banks with PCRs 0 - 23
19 are allocated.
20 Allocation is a list of banks and selected pcrs. The values should
22 follow the pcr bank specifiers standards, see section “PCR Bank Speci‐
23 fiers”.
24 The new allocations become effective after the next reboot.
26 Note: This command requires platform authorization.
28
30 • -P, --auth=AUTH:
31 Optional authorization value. Authorization values should follow the
33 “authorization formatting standards”, see section “Authorization For‐
34 matting”.
35 • ARGUMENT the command line argument specifies the PCR allocation.
37 References
40 The type of a context object, whether it is a handle or file name, is
41 determined according to the following logic in-order:
42 • If the argument is a file path, then the file is loaded as a restored
44 TPM transient object.
45 • If the argument is a prefix match on one of:
47 • owner: the owner hierarchy
49 • platform: the platform hierarchy
51 • endorsement: the endorsement hierarchy
53 • lockout: the lockout control persistent object
55 • If the argument argument can be loaded as a number it will be treat
57 as a handle, e.g. 0x81010013 and used directly._OBJECT_.
58
60 Authorization for use of an object in TPM2.0 can come in 3 different
61 forms: 1. Password 2. HMAC 3. Sessions
62 NOTE: “Authorizations default to the EMPTY PASSWORD when not speci‐
64 fied”.
65 Passwords
67 Passwords are interpreted in the following forms below using prefix
68 identifiers.
69 Note: By default passwords are assumed to be in the string form when
71 they do not have a prefix.
72 String
74 A string password, specified by prefix “str:” or it’s absence (raw
75 string without prefix) is not interpreted, and is directly used for au‐
76 thorization.
77 Examples
79 foobar
80 str:foobar
81 Hex-string
83 A hex-string password, specified by prefix “hex:” is converted from a
84 hexidecimal form into a byte array form, thus allowing passwords with
85 non-printable and/or terminal un-friendly characters.
86 Example
88 hex:0x1122334455667788
89 File
91 A file based password, specified be prefix “file:” should be the path
92 of a file containing the password to be read by the tool or a “-” to
93 use stdin. Storing passwords in files prevents information leakage,
94 passwords passed as options can be read from the process list or common
95 shell history features.
96 Examples
98 # to use stdin and be prompted
99 file:-
100 # to use a file from a path
102 file:path/to/password/file
103 # to echo a password via stdin:
105 echo foobar | tpm2_tool -p file:-
106 # to use a bash here-string via stdin:
108 tpm2_tool -p file:- <<< foobar
110 Sessions
112 When using a policy session to authorize the use of an object, prefix
113 the option argument with the session keyword. Then indicate a path to
114 a session file that was created with tpm2_startauthsession(1). Option‐
115 ally, if the session requires an auth value to be sent with the session
116 handle (eg policy password), then append a + and a string as described
117 in the Passwords section.
118 Examples
120 To use a session context file called session.ctx.
121 session:session.ctx
123 To use a session context file called session.ctx AND send the authvalue
125 mypassword.
126 session:session.ctx+mypassword
128 To use a session context file called session.ctx AND send the HEX auth‐
130 value 0x11223344.
131 session:session.ctx+hex:11223344
133 PCR Authorizations
135 You can satisfy a PCR policy using the “pcr:” prefix and the PCR mini‐
136 language. The PCR minilanguage is as follows:
137 <pcr-spec>=<raw-pcr-file>
138 The PCR spec is documented in in the section “PCR bank specifiers”.
140 The raw-pcr-file is an optional argument that contains the output of
142 the raw PCR contents as returned by tpm2_pcrread(1).
143 PCR bank specifiers (pcr.md)
145 Examples
147 To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifi‐
148 er of:
149 pcr:sha256:0,1,2,3
151 specifying AUTH.
153
155 Options that take algorithms support “nice-names”.
156 There are two major algorithm specification string classes, simple and
158 complex. Only certain algorithms will be accepted by the TPM, based on
159 usage and conditions.
160 Simple specifiers
162 These are strings with no additional specification data. When creating
163 objects, non-specified portions of an object are assumed to defaults.
164 You can find the list of known “Simple Specifiers Below”.
165 Asymmetric
167 • rsa
168 • ecc
170 Symmetric
172 • aes
173 • camellia
175 Hashing Algorithms
177 • sha1
178 • sha256
180 • sha384
182 • sha512
184 • sm3_256
186 • sha3_256
188 • sha3_384
190 • sha3_512
192 Keyed Hash
194 • hmac
195 • xor
197 Signing Schemes
199 • rsassa
200 • rsapss
202 • ecdsa
204 • ecdaa
206 • ecschnorr
208 Asymmetric Encryption Schemes
210 • oaep
211 • rsaes
213 • ecdh
215 Modes
217 • ctr
218 • ofb
220 • cbc
222 • cfb
224 • ecb
226 Misc
228 • null
229 Complex Specifiers
231 Objects, when specified for creation by the TPM, have numerous algo‐
232 rithms to populate in the public data. Things like type, scheme and
233 asymmetric details, key size, etc. Below is the general format for
234 specifying this data: <type>:<scheme>:<symmetric-details>
235 Type Specifiers
237 This portion of the complex algorithm specifier is required. The re‐
238 maining scheme and symmetric details will default based on the type
239 specified and the type of the object being created.
240 • aes - Default AES: aes128
242 • aes128<mode> - 128 bit AES with optional mode (ctr|ofb|cbc|cfb|ecb).
244 If mode is not specified, defaults to null.
245 • aes192<mode> - Same as aes128<mode>, except for a 192 bit key size.
247 • aes256<mode> - Same as aes128<mode>, except for a 256 bit key size.
249 • ecc - Elliptical Curve, defaults to ecc256.
251 • ecc192 - 192 bit ECC
253 • ecc224 - 224 bit ECC
255 • ecc256 - 256 bit ECC
257 • ecc384 - 384 bit ECC
259 • ecc521 - 521 bit ECC
261 • rsa - Default RSA: rsa2048
263 • rsa1024 - RSA with 1024 bit keysize.
265 • rsa2048 - RSA with 2048 bit keysize.
267 • rsa4096 - RSA with 4096 bit keysize.
269 Scheme Specifiers
271 Next, is an optional field, it can be skipped.
272 Schemes are usually Signing Schemes or Asymmetric Encryption Schemes.
274 Most signing schemes take a hash algorithm directly following the sign‐
275 ing scheme. If the hash algorithm is missing, it defaults to sha256.
276 Some take no arguments, and some take multiple arguments.
277 Hash Optional Scheme Specifiers
279 These scheme specifiers are followed by a dash and a valid hash algo‐
280 rithm, For example: oaep-sha256.
281 • oaep
283 • ecdh
285 • rsassa
287 • rsapss
289 • ecdsa
291 • ecschnorr
293 Multiple Option Scheme Specifiers
295 This scheme specifier is followed by a count (max size UINT16) then
296 followed by a dash(-) and a valid hash algorithm. * ecdaa For example,
297 ecdaa4-sha256. If no count is specified, it defaults to 4.
298 No Option Scheme Specifiers
300 This scheme specifier takes NO arguments. * rsaes
301 Symmetric Details Specifiers
303 This field is optional, and defaults based on the type of object being
304 created and it’s attributes. Generally, any valid Symmetric specifier
305 from the Type Specifiers list should work. If not specified, an asym‐
306 metric objects symmetric details defaults to aes128cfb.
307 Examples
309 Create an rsa2048 key with an rsaes asymmetric encryption scheme
310 tpm2_create -C parent.ctx -G rsa2048:rsaes -u key.pub -r key.priv
311 Create an ecc256 key with an ecdaa signing scheme with a count of 4 and
313 sha384 hash
314 /tpm2_create -C parent.ctx -G ecc256:ecdaa4-sha384 -u key.pub -r
315 key.priv cryptographic algorithms ALGORITHM.
316
318 Object Attributes are used to control various properties of created ob‐
319 jects. When specified as an option, either the raw bitfield mask or
320 “nice-names” may be used. The values can be found in Table 31 Part 2
321 of the TPM2.0 specification, which can be found here:
322 <https://trustedcomputinggroup.org/wp-content/uploads/TPM-
324 Rev-2.0-Part-2-Structures-01.38.pdf>
325 Nice names are calculated by taking the name field of table 31 and re‐
327 moving the prefix TPMA_OBJECT_ and lowercasing the result. Thus, TP‐
328 MA_OBJECT_FIXEDTPM becomes fixedtpm. Nice names can be joined using
329 the bitwise or “|” symbol.
330 For instance, to set The fields TPMA_OBJECT_FIXEDTPM, TPMA_OBJECT_NODA,
332 and TPMA_OBJECT_SIGN_ENCRYPT, the argument would be:
333 fixedtpm|noda|sign specifying the object attributes ATTRIBUTES.
335
337 PCR Bank Selection lists follow the below specification:
338 <BANK>:<PCR>[,<PCR>] or <BANK>:all
340 multiple banks may be separated by `+'.
342 For example:
344 sha1:3,4+sha256:all
346 will select PCRs 3 and 4 from the SHA1 bank and PCRs 0 to 23 from the
348 SHA256 bank.
349 Note
351 PCR Selections allow for up to 5 hash to pcr selection mappings. This
352 is a limitation in design in the single call to the tpm to get the pcr
353 values.
354
356 This collection of options are common to many programs and provide in‐
357 formation that many users may expect.
358 • -h, --help=[man|no-man]: Display the tools manpage. By default, it
360 attempts to invoke the manpager for the tool, however, on failure
361 will output a short tool summary. This is the same behavior if the
362 “man” option argument is specified, however if explicit “man” is re‐
363 quested, the tool will provide errors from man on stderr. If the
364 “no-man” option if specified, or the manpager fails, the short op‐
365 tions will be output to stdout.
366 To successfully use the manpages feature requires the manpages to be
368 installed or on MANPATH, See man(1) for more details.
369 • -v, --version: Display version information for this tool, supported
371 tctis and exit.
372 • -V, --verbose: Increase the information that the tool prints to the
374 console during its execution. When using this option the file and
375 line number are printed.
376 • -Q, --quiet: Silence normal tool output to stdout.
378 • -Z, --enable-errata: Enable the application of errata fixups. Useful
380 if an errata fixup needs to be applied to commands sent to the TPM.
381 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
382 formation many users may expect.
383
385 The TCTI or “Transmission Interface” is the communication mechanism
386 with the TPM. TCTIs can be changed for communication with TPMs across
387 different mediums.
388 To control the TCTI, the tools respect:
390 1. The command line option -T or --tcti
392 2. The environment variable: TPM2TOOLS_TCTI.
394 Note: The command line option always overrides the environment vari‐
396 able.
397 The current known TCTIs are:
399 • tabrmd - The resource manager, called tabrmd
401 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
402 abrmd as a tcti name are synonymous.
403 • mssim - Typically used for communicating to the TPM software simula‐
405 tor.
406 • device - Used when talking directly to a TPM device file.
408 • none - Do not initalize a connection with the TPM. Some tools allow
410 for off-tpm options and thus support not using a TCTI. Tools that do
411 not support it will error when attempted to be used without a TCTI
412 connection. Does not support ANY options and MUST BE presented as
413 the exact text of “none”.
414 The arguments to either the command line option or the environment
416 variable are in the form:
417 <tcti-name>:<tcti-option-config>
419 Specifying an empty string for either the <tcti-name> or <tcti-op‐
421 tion-config> results in the default being used for that portion respec‐
422 tively.
423 TCTI Defaults
425 When a TCTI is not specified, the default TCTI is searched for using
426 dlopen(3) semantics. The tools will search for tabrmd, device and
427 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
428 what TCTI will be chosen as the default by using the -v option to print
429 the version information. The “default-tcti” key-value pair will indi‐
430 cate which of the aforementioned TCTIs is the default.
431 Custom TCTIs
433 Any TCTI that implements the dynamic TCTI interface can be loaded. The
434 tools internally use dlopen(3), and the raw tcti-name value is used for
435 the lookup. Thus, this could be a path to the shared library, or a li‐
436 brary name as understood by dlopen(3) semantics.
437
439 This collection of options are used to configure the various known TCTI
440 modules available:
441 • device: For the device TCTI, the TPM character device file for use by
443 the device TCTI can be specified. The default is /dev/tpm0.
444 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI=“de‐
446 vice:/dev/tpm0”
447 • mssim: For the mssim TCTI, the domain name or IP address and port
449 number used by the simulator can be specified. The default are
450 127.0.0.1 and 2321.
451 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
453 TI=“mssim:host=localhost,port=2321”
454 • abrmd: For the abrmd TCTI, the configuration string format is a se‐
456 ries of simple key value pairs separated by a `,' character. Each
457 key and value string are separated by a `=' character.
458 • TCTI abrmd supports two keys:
460 1. `bus_name' : The name of the tabrmd service on the bus (a
462 string).
463 2. `bus_type' : The type of the dbus instance (a string) limited to
465 `session' and `system'.
466 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
468 ample.FooBar:
469 \--tcti=tabrmd:bus_name=com.example.FooBar
471 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
473 sion:
474 \--tcti:bus_type=session
476 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
478 ules.
479
481 To allocate the two default banks (SHA1 and SHA256)
482 tpm2_pcrallocate
483 To make a custom allocation with a platform authorization
485 tpm2_pcrallocate -P abc sha1:7,8,9,10,16,17,18,19+sha256:all
486 To completly switch from SHA1 bank to SHA256 with a platform authorization
488 tpm2_pcrallocate -P abc sha1:none+sha256:all
489
491 Tools can return any of the following codes:
492 • 0 - Success.
494 • 1 - General non-specific error.
496 • 2 - Options handling error.
498 • 3 - Authentication error.
500 • 4 - TCTI related error.
502 • 5 - Non supported scheme. Applicable to tpm2_testparams.
504
506 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
507
509 See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
510tpm2-tools tpm2_pcrallocate(1)